A process includes accessing a first message that is sent from an access point device. The first message includes data representing a second message that is sent by a client device. The second message is part of an exchange of messages between the client device and the access point device associated with authentication of the client device and a derivation of a first key used to encrypt and decrypt data communicated between the client device and the access point device. The second message includes a first message integrity check value. The process includes identifying, based on the second message, a pre-shared key corresponding to the client device. The identification of the pre-shared key includes determining a second message integrity check value based on a candidate pre-shared key of a plurality of candidate pre-shared keys; comparing the second message integrity check value with the first message integrity check value; and based on a result of the comparison, selecting the given candidate pre-shared key as the pre-shared key. The process includes determining a user role based on the pre-shared key. The process includes causing a third message to be sent to the access point device, where the third message includes data representing the pre-shared key and data representing the user role.